Opposite hemisphere differences in movement related potentials preceding foot and finger flexions

Area of Science:

• Neuroscience
• Motor Control
• Cognitive Neuroscience

Background:

• The readiness potential (RP) and contingent negative variation (CNV) are electrophysiological signals associated with motor preparation.
• Understanding the relationship between RP and CNV is crucial for elucidating motor preparation mechanisms.

Purpose of the Study:

• To investigate the relationship between RP and CNV during voluntary finger and foot movements.
• To explore whether motor preparation involves selective activation of specific cortical areas.

Main Methods:

• Simultaneous recording of RP and CNV in nine right-handed subjects.
• Voluntary finger or foot movement to press a microswitch, followed by a visual stimulus requiring a response.
• Electroencephalography (EEG) recorded at four electrode positions (C3, C4, C'3, C'4).

Main Results:

• RP amplitudes were larger over the hemisphere contralateral to finger movement.
• RP amplitudes showed a non-significant trend towards being larger ipsilateral to foot movement.
• Late CNV waves were larger at C3 before finger responses and at C'4 before foot responses.

Conclusions:

• The findings support a common underlying mechanism for late RP and CNV waves.
• Motor preparation appears to be a selective process linked to specific motor cortex area activation.